[Study of endothelin: distribution in the airway and release from nasal epithelial cells]

In order to clarify the existence and the role of endothelin in the respiratory tract, we investigated the distribution of endothelin in the respiratory mucosa by immunohistochemistry. The endothelin release from cultured nasal epithelial cells of allergic mucosa and polyp mucosa was also studied by RIA. Endothelin was distributed in the epithelium, endothelium of vessels, and submucosal glands in both nasal and bronchial mucosa. Moreover, in bronchial mucosa smooth muscles of bronchus had also positive staining of endothelin. On the other hand, 1.8 x 10(-11) pg of endothelin was released to culture medium from single cultured epithelial cell of allergic nasal mucosa, and 2.8 x 10(-11) pg of endothelin was released to culture medium from that of nasal polyp. These increase of endothelin was correlated with an increase of cultured epithelial cells from both nasal allergy mucosa and nasal polyp, of which the cell number was increased depend on the concentration of FCS. These results indicate that endothelin in the respiratory mucosa acts on not only control of blood flow and air flow, but also has some reaction which was related on the mucosal epithelium such as epithelial cilially movement. Endothelin has some role in inflammation because endothelin was increased more in nasal polyp culture medium than in allergic mucosa culture medium.